关键词: 异戊烷, 烷烃脱氢, 热力学, 烯烃, 氧化铝

Abstract: The thermodynamic equilibrium parameters of the main dehydrogenation reactions of isopentane to various mono-olefinand theoretical equilibrium conversion of isopentane were calculated.The product distribution and the effects of temperature, pressure and molar ratio of hydrogen to hydrocarbon on the equilibrium were analyzed.Simultaneously, the impacts of different process conditions on the reaction performance and product distribution on the Pt-Sn-M/Al₂O₃ catalyst were investigated by experiments.The results showed that the most abundant olefin produced by isopentane dehydrogenation was 2-methyl-2-butene, followed by 2-methyl-1-butene, and the least was 3-methyl-1-butene. High temperature, low pressure and low molar ratio of hydrogen to hydrocarbon were favorable for dehydrogenation reaction, but high temperature would lead to increase of side reactions such as cracking, and decrease of the selectivity of olefin. However, low pressure and low molar ratio of hydrogen to hydrocarbon could accelerate the coke deposition rate of the catalysts. The actual conversion of isopentane dehydrogenation testwas lower than the thermodynamic equilibrium calculated by thermodynamics. By selecting suitable test conditions, the conversion of isopentane dehydrogenation could be close to the thermodynamic equilibrium, which verified the reliability of the thermodynamic analysis results.

Key words: isopentane, alkane dehydrogenation, thermodynamics, olefin, alumina